A pair of hearing instruments may be worn on each side of a person's head to deliver stereo sounds to the person's ears. An example of such hearing instruments includes a pair of hearing aids that are used to assist a patient suffering hearing loss by transmitting amplified sounds to ear canals. The hearing aids are each worn in and/or around one of the patient's ears. It is desirable to deliver sounds to both ears in a way that provide for perception of a realistic sound environment. For example, use of two microphones, one in each of the hearing aids, may allow for perception of sounds with directionality, This requires the sound sensing/receiving, amplification, and delivery into ear canals to be coordinated between the hearing instruments.